1. Field of the Invention
The present invention relates to unique variant of laser ablation transfer ("LAT") imaging onto special intermediate receptor elements that are well suited for secondary or downstream blanketwise lamination of both the image and, advantageously, a protective overcoating therefor, to a wide variety of ultimate substrates.
Representative applications of such "LAT decalcomania" techniques according to this invention include the production of matte or glossy full-color prints or proofs, and desirable monochrome photomasking films.
2. Description of the Prior Art/Current State-of-the-Art
U.S. Pat. No. 5,156,938 to Diane M. Foley et al, assigned to the assignee hereof and hereby expressly incorporated by reference and relied upon, recounts the laser ablation transfer imaging science ("LATIS") prior art and describes a unique method/system for simultaneously creating and transferring a contrasting pattern of intelligence on and from an ablation-transfer imaging medium to a receptor element in contiguous registration therewith that is not dependent upon contrast imaging materials that must absorb the imaging radiation, typically laser radiation, and is well adopted for such applications as, e.g., color proofing and printing, computer-to-plate, the security coding of various documents and the production of machine-readable or medical items, as well as for the production of masks for the graphic arts and printed circuit industries; the ablation-transfer imaging medium, per se, comprises a support substrate and an imaging radiation-, preferably a laser radiation-ablative topcoat essentially coextensive therewith, such ablative topcoat having a non-imaging ablation sensitizer and an imaging amount of a non-ablation sensitizing contrast imaging material ("CIM") contained therein.
U.S. Pat. No. 5,171,650 to Ellis et al, also assigned to the assignee hereof and hereby also expressly incorporated by reference and relied upon, describes improved ablation-transfer imaging media having greater sensitivity, requiring less sensitizer and threshold energy (thus permitting a greater range of mass to be transferred), and which additionally are kinetically more rapid and facilitate the ablative transfer to a receptor element of an imaging radiation-ablative topcoat containing virtually any type of contrast imaging material (whether sensitizing or non-sensitizing).
Such method/system of the '650 Ellis et al patent for simultaneously creating and transferring a contrasting pattern of intelligence on and from a composite ablation-transfer imaging medium to a receptor element in contiguous registration therewith is improvedly radiation sensitive and versatile, is kinetically rapid and not dependent on a sensitized ablative topcoat, and is also very well adopted for such applications as, e.g., color proofing and printing, computer-to-plate, the security coding of various documents and the production of machine-readable or medical items, as well as for the production of masks for the graphic arts and printed circuit industries; the Ellis et al composite ablation-transfer imaging medium, per se, comprises a support substrate (i), at least one intermediate "dynamic release layer" (ii) essentially coextensive therewith and an imaging radiation-ablative carrier topcoat (iii) also essentially coextensive therewith, said imaging radiation-ablative carrier topcoat (iii) including an imaging amount of a contrast imaging material contained therein, whether or not itself including a laser absorber/sensitizer, and said at least one dynamic release layer (ii) absorbing such imaging radiation, typically laser radiation, at a rate sufficient to effect the imagewise ablation mass transfer of at least said carrier topcoat (iii).
By "dynamic release layer" is intended an intermediate layer that must interact with the imaging radiation to effect imagewise ablative transfer of at least the carrier topcoat onto a receptor element at an energy/fluence less than would be required in the absence thereof. The dynamic release layer ("DRL") is believed to release the carrier topcoat by effectively eliminating the adhesive forces that bond or consolidate the carrier topcoat with the support substrate. Preferably, under the same conditions additional propulsion is simultaneously provided by the interaction of the imaging radiation therewith, e.g., by ablation of the dynamic release layer itself, thus further facilitating the imagewise ablative transfer of the entire carrier topcoat to a receptor element. Representative DRLs per Ellis et al include metal, metal alloy, metal oxide and metal sulfide thin films, etc., and the organics.
Thus, the LAT imaging films employed in, for example, the Foley et al and Ellis et al LATIS' described above have essentially been limited to those "permanent" films available from inventory, namely, pre-manufactured or pre-coated, and, hence, which inventory is typically inadequate to supply the complete spectrum of LAT imaging films that may be required for a particular application, e.g., not all colors, not all color densities, not all film thicknesses, etc., are usually available from inventory.
Consequently, unique means have now been developed, described in Ellis copending application Ser. No. 07/978,482, filed Nov. 18, 1992, now abandoned, also assigned to the assignee hereof, for the on-demand or on-line production or generation, of LATIS imaging films that offers the end user a degree of flexibility and versatility hitherto alien to this art.
Such on-demand production/generation of LAT imaging films presents any one or more of an essentially infinite number of contrast imaging material options, as well any one or more of an essentially infinite number of thicknesses and CIM densities.
Too, such unique means for the on-demand production/generation of LATIS imaging films entails conventional toning techniques utilizing conventional liquid or dry toners, or liquid or dry toners especially modified or customized as to be tailored to a specific desire or LATIS application. Indeed, conventional or customized toners are employed that offer the option, whether from an economic and/or environmental standpoint, of recycling the unused toner from the non-imaged areas on imaged donor films.
The composite LAT imaging films described in the '482 Ellis application comprise a discontinuous or "toned" ablative topcoat and, hence, are improvedly laser radiation sensitive (by reason of the reduced adhesion of the discontinuous ablative topcoat to whatever substrate, whether or not including a DRL, in contradistinction to LAT imaging films which comprise a permanent, durably adhered continuous ablative topcoat).
In sum, the '482 Ellis application features the on-demand supply of appropriate substrate that will ultimately comprise the desired LAT film, and then on-site toning such substrate as to provide a unique composite film having a desired color or imaging functionality at a desired thickness or density, typically just prior to or immediately upstream of the actual imaging sequence.
To date, though, the state of the LATIS art has proven somewhat inflexible in that the known LAT techniques have essentially been limited to image transfer to one particular receptor element, itself strictly governing final image density, product morphology, amount of energy required for transfer, dimensionality of viewing of the final product, and the like.